I have Katniss Everdeen and Mary Winchester up for grabs.
I don't think Eric Northman would make a good partner for this plot but if someone wants to pair with him, that's fine, otherwise, I can just keep him out of play for plot. The reason I think that he wouldn't make a good partner is because he has to be in a light tight room during the day (he burns in the sun) when he's dead to the world. I think it would be very limiting on the character that is paired with him.